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• Ti L- and O K-edge of Li, Na, K, and Mg-intercalated multi-layered Ti 3 C2T x particles. • Ti oxidation state of multi-layered cation-Ti 3 C 2 T x particles. • Thickness-dependent is observed in cation-Ti 3 C 2 T x. Ti 3 C 2 T x MXene is a two dimensional (2D) material possessing highly active hydrophilic surfaces coupled with high metallic conductivity. Cation intercalation between the Ti 3 C 2 T x nanosheets has a significant role in many applications such as water purification, desalination, and electrochemical energy storage. The pseudocapacitive charging mechanism involving surface redox reactions at the Ti 3 C 2 T x surface enables higher energy densities than electrical double-layer capacitors, and higher power densities than batteries. In this context, the oxidation state of surface Ti atoms involved in redox reactions has a high impact on the capacitance of Ti 3 C 2 T x MXene and this can be impacted by cation intercalation. The electronic structure of multi-layered Ti 3 C 2 T x particles can be investigated by X-ray absorption (XA) spectroscopy, while also benefitting from a high spatial resolution of 30 nm from X-ray photoemission electron microscopy. In this work, the XA spectra from multi-layered intercalated Ti 3 C 2 T x particles of different thicknesses were recorded at the Ti L- and O K-edges. The Ti oxidation state in pristine, Li-, and Mg-intercalated Ti 3 C 2 T x was found to be thickness-dependent, while Na- and K-intercalated Ti 3 C 2 T x particles did not reveal differences upon changing thickness. This work demonstrates thickness-dependent modification of the MXene surface chemistry upon cation intercalation in different individual Ti 3 C 2 T x particles. [ABSTRACT FROM AUTHOR]